The invention discloses an interval-frame difference method based detection method of driving vehicle in a front lane line; the detection method comprises the following steps: firstly reading real time traffic images and extracting continuous four frames of color images; carrying out graying processing for the images; combining Hough conversion and projection method so as to extract a partial zone in the front lane line of the vehicle in the image; using Gauss filter smooth processing to remove partial noises; using the interval-frame difference method after previous treatments; calculating from the read first frame image; using the third frame image to subtract the first frame image so as to obtain a first frame difference image; using the fourth frame image to subtract the second frame image so as to obtain a second frame difference image; converting the two frame difference images into binary images according to a preset threshold; finally subtracting the two binary images so as to obtain an absolute value, and thus obtaining a final detection result.